Method for increasing the oiliness value of lubricating oils and lubricating oils prepared by such method



' 1 .t.,..e.1 J.....-,2i,19s8 a I 2,121,976

UNI TED; STATES PATENT OFFICE 1 I g I 2,12l,976 l.

BRICATING OILS PREPARED BY SUCH METHOD Louis A. Mikeska and Charles A. Cohen, Eliza beth, N. J., assignors to Standard Oil Development Company, a corporation of Delaware Nd Drawing. Application December 29, 1934,

' Serial N0.759,'l36

l rally endowed with a sufllcient degree of oiliness about one-half hour. I

The presentinvention relates to methods'for sired result. The treatment may be carried out 1 improvlnglubricating oils especially in respect to in the cold, but it is greatly improved if the ester their oiliness characteristicsand more specifically material is maintained in a heated conditionl As to blendedmineral-oil lubricants containing esters, will be understood, the p t r Should not 5 in relatively small concentrations. a be sumciently high to bring about substantial de- 5 l There has been considerable attention given, o p and in general temperatures r .during the past few years to vmethods for im- 100 to 150 C. have been found to be satisfactory.- proving lubricating oils especially in respect to At these tempe at es w a good grade y, their -ollin'ess values. Mineral oils are not natuthe treatment may usually be accomplished in for many of, the lubricating problems of the pres- The materials which will be imp e by the ent time and this has been remedied most sucprocess outlined above broadly in l r cessfully by the addition of small amounts of high particularly those having boiling points above boiling esters to the mineral lubricating oil. about 150 C. Fats and fatty s ay be u as Various ester, materialshave been used and a W811 asfihe n t l Waxes- Among Such mateconsiderable increase in the ciliness value is obrials y b noted rapeseed W001 Sperm tamed by the addition of almost any type o'foil and the like, olive oil, menhaden oil, lard oil ester. However, it is found that'the synthetic and their q l s. M d fi d atu a oils ay esters are generally better than the naturally also be used, in particular those naturally conv occurring esters such as arefound in the fats taming unsaturated bonds y y E P 20 and fatty oils. It has now'been found that these Th may be fi f r mp by s erifica materials whether natural or artificial can be tion, such asacetylation and/or by hydrogenation considerably improved by treatment with sorptive orby both o these treatmentsy flt to (i. e. absorptive or adsorptive) nateilals, and oil or wool oil and hydrogenated acetylated caster :5 while the reason for the improvement is not 1 y b cited 95 an example Q ype 01 known at the r nt t is believed to mat rial. Modified esters, such asthose obtained due to the removal of relatively small amounts of ,by blecting na r y Occurring f ty O l I substances of'unknown constitutionwhich-pre- 'or the esters contained therein, to treatments vent the esters from accomplishing their best recausing a substantial change in their viscosity or sults. This is believed to'be the case not only solubility characteristics, are included within the 30 with the naturalv but also-with synthetically 'preclass of synthetic esters of the present invention pared esters. and the claims.

'lhe treatment, as stated above, is accomplished Among the synthetically prepared esters may by the action of sorptive 'materials. Among be included generally the mono diand polythese, the active clays, suchyas for example the v alcoholic esters of acids of the class of oleic .and 35 commerclal clays which are sold under the, fol- .stearic or of naphthenic' acids such as are delowing names: fullers earth, 'Attapulgus clay, rived om some of the crude petroleums, The. Terrana clay, Marsil clay and Eloridin clay, are acids derived from paraffin wax by oxidation at perhaps the most desirable, but other. sorptivc. 10W la r f om h h y purifi min- 40 agents such as alumina, sillcaand active carbon eral oils may be used. 'Ihese'synthetic esters may 40 may also be used, depending-upon the nature of be made from all of the alcohols ranging from the material to be treated. .Th'e treatmentmay the short chain members of the type of ethyl consist either in percolation through a bed of the and isopr y 911691101 p to the higher members sorptive material or agitation with a relatively' of the series such as lauryl decy Low 4.5 small amount of the material which can then be molecular weight acids such as acetic or propionic 4.3 separated by filtration. Ordinarily, from about -may"be used especially where a high molecular 1 to of clay or other alkaline solid sorptlve' weight alcohol or 'hydroxylated body is employed. agent may be used, that is from 1 to 40 pounds Estersof inorganic acids,- as for example triof clay per barrel of the ester, but preferably becresyl phosphate, dibutyl phthalate, amyl borate,

tween 4 to 10, lbs. per barrel. .The contact should and the like are contemplated. v 50 be maintained for a 'suillcient period, which del The amount of the ester may vary from about pends on several factors, such as temperature, 1 6 to 5%, more or less, but ordinarilyfrom 1 the particular nature of the ester, the sorptive to 3% is employed in order to'produce ,a good material used. Generally, a percolation period grade of motor oil or a motor oil which might of 15 to 45 minutes is sufllcient to produce the debe used not only generally for the lubrication 55 oi.- automotive engines but also for the purpose of breamng in" new or "green" engines. The es tors are preferably treated with the sorptive agent before it is added to the mineral oil but the treatment may be carried out after mixing of these two ingredients, although this method generally requires more time or a larger quantity of treating agent.

The present treatment method is 'not intended to take the place of other refining methodsto which ester materials may be subjected, but is designed to increase the oiliness property of the ester blends'in addition to ordinary purification in respect to color, odor. and the like.

The oils which may be blended with the agents disclosed above. range from the lightest to theheaviest grades made from petroleum oils, andwhile they may be used generally for all purposes to which lubricants of the type are ordinarily put, they are particularly advantageous for the lubrication of automotive engines; For this purpose, they may be added to all of the S. A. E. grades of motor lubricating oils, both the winter and summer grades.

No particular specifications need be given for the oil used in the above blends but crude, partially refined, or highly refined, may be employed,

although they are preferably well refined and may be produced by the ordinary methods of petroleum refining, such as treatment with acid and alkali, or by the special methods involving hydrogenation, destructive hydrogenation or solvent extraction.

The lubricating oil blendsmay contain other ingredients besides the oiliness agents, for example, dyes, pour inhibitors, soaps, sludge dispersers and oxidation inhibitors and the like. None ExampleJ Sperm oil was esterifled with acetic. acid by means of a. small amount of sulphuric acid.. The reaction was carried out in benzol solution and the product was carefully washed, freed of acid and benzol and dried.

One sample of this ester prepared as above was treated with 10% by weight of Attapulgus clay by agitation at C. for about 1 hour, afterwhich the clay was removed by filtration.

Blends were now prepared by adding 2% of the clay treated and of the untreated ester respectively to different samples of an S. A. E. 20 lubricating oil. These blends were then tested on the Mougey machine according to the method described in National Petroleum News, November 11, 1931, at page 4'7. The blend containing the clay treated ester carried the full 25 weights of the specified test with a final. friction of 20 ft.

pounds, while the untreated ester carried the 25 weights but with a frictional value of 65 ft. pounds.

Both esters greatly improved the oiliness value of the mineral oil but the clay treated ester was considerably more effective than the untreated Example 11 weight. A similar blend of a clay treated ester carried 25 weights with a frictional value of 100 ft. pounds.

A mixture of higher alcohols was separated from a paraflin wax oxidation product and was esterified with acetic acid. As in" previous examples, blends were made up with 2% of such esters treated with 10% of clay and untreated respectively. Both samples carried the 25 weights on the Mougey machine, but whereas the final friction was 34 ft. pounds .with the ester which had not been treated, it was only 23 with the clay treated sample.

The present invention is not to be limited by any theory of the mechanism of the oil agent nor of the method for improving its oiliness properties nor indeed to any particular absorptive agent or ester material but only to the following claims in which it is desired to claim all novelty inherent in the invention.

We claim:

1. Improved lubricating oil composition comprising a mineral lubricating oil containin dissolved therein a small amount of a synthetic ester boiling above C. and having the characteristics of increasing the oiliness of said lubrieating oiL'said ester having been treated to improve its oiliness properties with a solid sorptive agent without subsequent heating sufficient to cause decomposition or polymerization of the adsorptive agent of the type of clay.'

3. Composition according to claim 1 in which a synthetic ester is used which has been subjected to treatment with clay at a temperature from 100 to 150 C. for a tim'e'sufficient to improve its oiliness properties.

4. Composition according to claim 1 containing from to 5% of a synthetic ester boiling above 150 C, which has been subjected to treatment with adsorptive clay for about hour at a temperature from 100 to 150 C.

5. Method for preparing improved lubricating oil compositions ofhigh oiliness characteristics, comprising subjecting a synthetic ester boiling -a.bove 150 C. and having the characteristic of increasing the oiliness value of mineral lubricating oils, to treatment with a solid sorptive agent in order to improve the oiliness properties of said ester and dissolving. a. small amountof the thus treated ester without subsequent heating sufiicient to cause decomposition or polymerization thereof, in a mineral lubricating oil.

6. Composition according to claim 1, in which said organic acid is a fatty acid.

7. Composition according to claim 1, in which said ester is a synthetic ester of a high molecular weight aliphatic alcohol and a low molecular weight fatty acid." I

8. Method according to claim 5 in which said sorptive agent is an adsorptive clay.

9. Method according to claim 5 in which said treatment comprises subjecting the ester to contact with an adsorptive clay at a temperature of about 100 to 150 C.

10. Method according to claim 5 in which the resulting composition contains about 0.1% to 5% of said treated ester.

LOUIS A. MIKESKA. CHARLES A. COHEN. 

